Hume R I, Dingledine R, Heinemann S F
Molecular Neurobiology Laboratory, Salk Institute, La Jolla, CA 92037.
Science. 1991 Aug 30;253(5023):1028-31. doi: 10.1126/science.1653450.
The neurotransmitter glutamate mediates excitatory synaptic transmission throughout the brain. A family of genes encoding subunits of the non-N-methyl-D-aspartate (non-NMDA) type of glutamate receptor has been cloned. Some combinations of these subunits assemble into receptors with a substantial permeability to calcium, whereas others do not. To investigate the structural features that control ion permeation through these ligand-gated channels, mutant receptor subunits with single-amino acid changes were constructed. Mutation of a certain amino acid that results in a net charge change (from glutamine to arginine or vice versa) alters both the current-voltage relation and the calcium permeability of non-NMDA receptors. A site has thus been identified that regulates the permeation properties of these glutamate receptors.
神经递质谷氨酸介导全脑的兴奋性突触传递。一个编码非N-甲基-D-天冬氨酸（非NMDA）型谷氨酸受体亚基的基因家族已被克隆。这些亚基的某些组合组装成对钙具有相当通透性的受体，而其他组合则不然。为了研究控制通过这些配体门控通道的离子通透的结构特征，构建了具有单氨基酸变化的突变受体亚基。导致净电荷变化（从谷氨酰胺变为精氨酸或反之亦然）的某个氨基酸的突变会改变非NMDA受体的电流-电压关系和钙通透性。因此已确定了一个调节这些谷氨酸受体通透特性的位点。
